De-icer for aeroplanes and the like



1932- w. c. GEER 1,890,286

DEICER FOR AEROPLANES AND THE LIKE Filed May 12. 1932 5 I My PatentedDec. 6, 1932 UNITED STATES WILLIAM G. GEEB, OF ITHACA, NEW YORK DE-ICERFOR AEBOPLANES AND THE LIKE Application filed Kay 12,

This invention'relates to devices for preventing accumulation of iceupon parts of aeroplanes or the like, especially parts of smallcross-section such as struts and wires,

and its chief objects are lightness, simplicity and economy ofconstruction, and automatic operation. I Of the accompanying drawing:Fig. 1 is a front elevation of an aeroplane equipped with an embodimentof my 1nven'- tion in its preferred form. V

Fig. 2 is a perspective sectional view of one of the elements of theembodiment, in an unstrained condition. H

Fig. 3 is a cross-section of the same in operation, the unstrainedposition of a part of the structure being shown in broken lines.

Fig. 4 is a perspective sectional view of one of the elements of amodification, in an unstrained condition.

Fig. 5 is a similar view another modification.

Referring to the drawing, stream-line brace wires of anaeroplane areshown at 10, 10.

Embracing each wire is a rubberizedfabric sheath 11 serving as ananchorage fona transverse flexible or vibrator sheet of deformablematerial such as vulcanized rubber composir tion, which along its middlelineis vulcanized or otherwise secured to the sheath 11, on the forwardside of the latter, and adapted to vary its shape under the force of theairstream when the aeroplane is in flight, to break up the ice anddislodge it from its surof an element of 1 face, and also to shield thesheath behind it from the formation of ice thereon.

The flexible sheet, in unstrained condition, may be of the plane formshown at 12 in Fig. 2, of the forwardly concave form shown at 13 in Fig.4, or maybe of planeor other form and slotted inward from each side atintervals as shown at 14, 14 in Fig. 5. i I l In flight the transversesheet is flexed by the air-stream as shown in Fig. 3, its flexurevarying as the air speed of the aeroplane varies, so that ice forminupon its surface is broken up and dislodged, and a fluttering orperiodic vibration of the sheet also may be produced with very effectivedislodgement of the ice as the result.

im re natin the rubber preferably is a liq- P g g contact with rubber.

1932. Serial No. 610L840.

The rubber sheet preferably has mixed therein or applied thereto asubstance adapted to lessen its adhesion to the ice.

The water-repellent material to be used for uid and the liquid to beused for this purpose should be one which has a freezing point below theice-forming temperatures and which is fluid at these temperatures. Itshould be of low viscosity at thesetemperatures and should not besticky, and hence adhesive toward ice. It should also be'material whichwill be absorbed into the rubber, but which will not swell or weaken therubber to such an extent that it would have insufficient tensilestrength .for the use to which it is applied. Itis also important thatthe liquid be of relatively high boiling point in orderthat it may notevaporate from the surface at the high temperature to which it may besubjected.

It isdesirable that the li uid be such that it may be applied to therubber without substantially deteriorating the rubber surface; that itwill reduce the adhesion of the ice to the surface and yet will notevaporate from the surface at ordinary temperatures; that the rubberwill have a substantially dry surface at ordinary temperatures; and thatit will exude from the rubber at ice-forming temperatures. v

A large number of oils are absorbed into vulcanized rubber, butordinarily with the result that the rubber is thereby caused to swell toa greater or less extent and consequently its tensile strength and otherphysical properties are more or less weakened. Be-

'cause of this effect it has been generally considered to be'undesirableto use most oils in I have'found that by mixing with an oil which willbe absorbed into the rubber surface and give the desired lubricating'ornon-adhesive characteristics, a liquid which isinsoluble in the rubberand which will prevent swelling thereof, a composition will be producedwhich will give the desired surface and which will not substantiallyswell or otherwise deteriorate the rubber.

One of the following liquids of low freezing point and relatively highboiling point may be added to a rubber surface and will substantiallydecrease the adhesion of ice to the surface.

Theaddition of one of these liquids to vulcanized rubber will, however,cause the rubber to swell and will decrease its tensile strength. Byadding a liquid such as diethyl phthalate or butyl tartrate to one ofthe above oils, the swelling of the rubber and the decrease in tensilestrength will be greatly reduced. If the two liquids to be mixed are notmiscible with each other, they may be brought into common solution byadd ng a liquid capable of dissolving both of them. For example, diethylphthalate and pine oil, which are mutually immiscible, may be broughtinto solution by adding castor oil, which in itself is insoluble inrubber and therefore further reduces the swelling of the rubber.

As an example of a suitable composition to be applied to a rubbersurface, and which will reduce the adhesion of ice to the rubbersurface, the following substances may be mixed in the proportionsstated:

' V Parts by volume Pine oil 4 Diethyl phthalate 4 Castor oil 1 Thisparticular mixture has the added advantage that its solubility in rubberis reduced at the ice forming temperatures, so that at thesetemperatureg it will exude from and render the surface we'll lubricatedWhile it will produce a substantially'dry. surface in the rubber atordinary temperatures.

When this mixture is applied to a vulcanized rubber of the compositionhereinafterdescribed for use in preventing the accumulation of ice uponaircrafts, the oil will exude from the surface at the ice formingtemperature and replace any oil which may be removed from the surface bythe air forces, by vaporization or by removal with the ice. Additionaloil may be applied from time to time as the supply is exhausted. WVhen aneutral oil which does not radically alter the physical properties ofthe rubber is absorbed in rubber the rubber is actually preservedagainst oxidation.

Any rubber mixture, capable of satisfactory vulcanization, may be usedfor producing the rubber surface."the following typical mixture beinggiven as an example of such a composition Parts Smoked sheet; 100 Zincoxide 10 Sulfur; 3 Accelerator 1 larities into which water mightpenetrate and. upon freezing, anchor itself.

When a' vulcanized rubber of the above described composition is soakedin pure pine oil for 24 hours, its average increase in volume will begreater than 50%, and its average decrease in tensile strength will begreater than However, when a vulcanized rubber of the same compositionis soaked for 24 hours in the mixture of oils referred to above, it wasfound to have an increase in weight of about 19%, an increase in gaugeor volume of about 7 and an average decrease in tensile strength ofabout 12 70. It is apparent, therefore, that although an appreciableweight of oil had been absorbed into the rubber. the volume had beenonly relatively slightly increased and the tensile strength had been butmoderately-affected.

Although I have described a particular mixture of liquids, it is notintended to thereby limit the invention to the specific liquids orproportions mentioned. Other vegetable. mineral or synthetic oils may beused to give the desired lubricating or reduced adhesioncharacteristics. Other liquids than those described may also be added tosuch oils to reduce the swelling of the rubber and the resultantdecrease in tensile strength and deterioration of other physicalproperties. Such liquids may be alcohols, ketoncs and other esters whichpossess the property ofmixing with nitrocellulose or, as hereinbcforeindicated, castor oil. The boiling point and freez ng point may beunimportant in the Various modifications are possible within the scopeof theinvention as defined in the appended claims.

I claim;

1. In combination with a member exposed to ice-forming conditions in anair-stream, a transversely disposed sheet of deformable material securedalong its middle line only to the said member. a

2. In combination with a member expose to ice-forming conditions in anair-stream, a sheath embracing the memberand a transversely disposedstrip of deformable material anchored along a longitudinal zone thereofto the sheath in position to be agitated by the air-stream. I 3. Incombination with a member exposed to ice-forming conditions in anair-stream, a strip of vulcanized rubber composition extending along thesaid member and having a portion freely projecting laterally from saidmember when in an unstrained condition and thus so disposed as to beagitated by the air-stream.

4. In combination with a member exposed to ice-forming conditions in'anair-stream, a sheath embracing the member and a transverselydisposed'strip of deformable material anchored along a longitudinal zonethere-' of to the sheath in position to be agitated by the air-streamand a surface film of ad- I hesion-preventing material on said strip.

5. In combination with a brace-wire of an I aeroplane a strip ofdeformable material extending along the wire and having a portion freelyprojecting laterally from the wire when in an unstrained condition andthus adapted to be deformed to dislodge ice therefrom. v

6. In combination with a brace-wire of an aeroplane a strip ofdeformable material extending along the wire and having a portion freelyprojecting laterally from the Wire when in an unstrained condition andthus adapted to be deformed by the air-stream to dislodge .icetherefrom. a 7 In combination with a brace-wire of an, aeroplane a stripof deformable material extending along the wire and adapted to bedeformed by the air-stream to dislodge ice therefrom, the said stripbeing concave on its 'forward side when in an unstrained condition,

8. In combination with a brace-wire of an aeroplane a strip ofdeformable material extending along the wire and 'adapted'to be de-'formed by the air-stream to dislodge ice therefrom, the said strip beingslit inwardly from its margins at intervals. a In witness whereof I havehereunto set my hand this 9th day of May, 1932. a z WILLIAM G. GEER.

